


Dragon Eggs

by idontevenknowugh



Category: Undertale (Video Game)
Genre: Established Relationship, Mpreg, Other, Oviposition, Soul Sex, skele preg, vore mentions
Language: English
Status: Completed
Published: 2018-06-13
Updated: 2018-06-13
Packaged: 2019-05-21 20:20:01
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,398
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14922185
Author URL: https://archiveofourown.org/users/idontevenknowugh/pseuds/idontevenknowugh
Summary: Sans and Kern are ready to take the next step.





	Dragon Eggs

**Author's Note:**

  * Inspired by [[vore] Sans and the Dragon](https://archiveofourown.org/works/10181729) by [wolfbunny](https://archiveofourown.org/users/wolfbunny/pseuds/wolfbunny). 



> Thank you so much to Lyco ([AO3](https://archiveofourown.org/users/wolfbunny/pseuds/wolfbunny)|[Tumblr](http://nom-the-skel.tumblr.com/)) for commissioning me. I tried do give your characters justice. ^_^

Kern’s tongue flickered across Sans’s femur, licking up it and to his pelvis. The dragon wasn’t usually hesitant, but he paused as his tongue met San’s magical construct before exploring it with his tongue.

“I’m not sure this is the most efficient way,” Kern said between licks as he made several more passes over the ‘flesh’. Sans gasped and snorted, the magic sensitive. His legs kicked slightly as the unexpected sensation tingled out from the spot. “It seems like it would make more sense to go in through the space under your ribs.” He followed up the opinion by nosing around the sack Sans had made with his magic, where it sat in that very space.

“Stop that,” Sans giggled, and pushed at Kern’s snout. “Well since you don’t know how it’s supposed to be done, I went based off of human anatomy- I’m human-shaped- and this is as close as they had.”

“Hm,” Kern replied noncommittally and licked at the front of it. “I do like this new trick of yours. Tasty.”

“Kern,” Sans whined. That tickled even more. Kern gave the flesh a parting lick before sitting back. He was in one of his smaller form. On his haunches on the bed, he looked particularly dog-like.

“You seem nervous,” he licked his chops once and tilted his head at Sans.

“Well, we don’t exactly know what we’re doing,” Sans said dryly.

“It will be fine,” Kern assured him, with a flick of his tail. “I wouldn’t hurt you.”

Sans knew he was telling the truth, but there was still a lot that could go wrong. He wasn’t going to back out or anything. Sans wanted this as much as Kern did. It just made him a little anxious that not even Kern knew the process. All they had to rely on was instinct.

Kern took the silence as a chance to return to his inspection of Sans’s pelvis. He was dwelling, too. Sans wondered if if Kern was a little nervous. If so, he didn’t say anything. He did shove his snout under Sans’s pelvis, lifting it off the bed.

Sans yelped, balancing himself with his hands and feet.

“What are you doing?” he asked, breathless from being startled. Kern wiggled his head back out, letting Sans fall to soft mattress.

“It’s too low. I’m going to need to raise it,” he said absently, not answering the question at all.

That was it, and then Kern was bounding up and down the bed, pillows retrieved from the headboard set next to Sans. He considered the pile for a moment before jumping off the bed and sticking his head in the closet. Some other pillows appeared, that Sans didn’t even know they had, and were also dragged to the bed.

Kern started to grow until he was able to stand over the bed and Sans. He was still gentle as he lifted Sans’s legs, stuffing the pillows underneath his pelvis.

“Woah!” Sans yelped. He grabbed the bed, grounding himself against the sudden activity. Kern gave his foot a lick, but continued until all the pillows were piled up and Sans was laying at an incline with his pelvis high up. Kern let go of his legs, and they flopped down on the opposite side of the pillow mountain.

Sans huffed, but stayed put as Kern shuffled about doing something else. He was used to Kern’s brashness, and if it meant he was going to do all the work, Sans could live with it.

“Okay, we’re ready,” Kern announced, snuffling around Sans one more time.

“Speak for yourself,” Sans retorted, but did a final readjust before relaxing. Kern gave him what might have actually been a concerned look before crawling over him.

There had been some method to the pillow madness, apparently. Kern’s forearms rested on the bed above Sans while his rear stayed on the ground. Sans’s sloped position meant that the entrance of his magical construct rested up against the opening that Kern had made him aware of a few weeks ago.

“Don't you think that's a little big?” Sans asked nervously.

“I have to get the eggs out,” Kern stretched his long neck out so his head was visible and tilted it.

How big were the eggs? Sans couldn't sit up to look at the dragon, so he had to go back to trusting him. Still, there was an anxious energy in him now. Every movement and touch from Kern made him jump.

Eventually it was time, and a new sensation started down by his pelvis. It was something smooth and warm, its curved top pressing against the opening of the magic sack. Kern grunted, his head swaying back and forth with the effort. It was distracting, so Sans looked away, staring at their bedroom wall.

The egg inched forward, the curve parting the magical flesh slowly. It was going to be tight, Sans realized, as the egg kept getting wider. He spread his legs, pointlessly. There was nothing he could do about the width of his inlet. Maybe Kern had had a point about the method, but it was too late now.

The egg finally stopped widening and started to really move through Sans. It was wide enough to be uncomfortable, especially as it squished the magical flesh against his pelvic inlet, but Sans had given it enough stretch that it didn't hurt.

One concern he'd had was getting the eggs up to the sack, so he had done more research and found out some very disturbing facts about humans. It had all led him, however, to include something like the muscle impulse humans used to move things around their bodies. Sans just had to concentrate on his.

“Ngh,” Sans groaned as he focused on making the magical construct move. Ripples went through the tube the egg sat in, and it started the slow trek up to the sack.

“Fascinating,” Kern commented, sounding a little out of breath. He stopped moving to watch the egg’s progress, until it slid free of the tube and into its new home. Sans glanced up at Kern, who looked strangely struck by what he saw. When he noticed Sans looking at him, he lowered his head and licked the sack before pressing their bodies firmly together again.

Sans, flushed from the display of affection, kept focusing on his magic. Once the next egg was halfway into him, his body started to pull it along, speeding up the process. Kern didn't stop this time, following that egg up with the next one, so there were two stretching him open.

That was well and good with Sans. He was eager to finish the process and have the eggs secure inside of him. They had spent two weeks in Kern, absorbing his magic into their makeup. Now they would stay in Sans for two weeks, doing the same.

The two eggs made the journey safely to join their sibling. They weren't joined by another, so Sans’s magic had a chance to relax. Maybe that was it. Kern hadn't been able to tell how many eggs he had been growing. Three was already a good number of kids to raise.

His soul gave a little squeeze at the thought. He wanted these little ones, he really did, but he wasn't quite confident that he could do right by them. Sans wasn’t known for his responsible nature. The moment Papyrus had been old enough to take over the house, Sans had let him. Now, he would be able to rely on Kern to pick up the slack when Sans didn’t do his part, a thought that caused a flood of guilt.

“Is that-” Sans started to ask if Kern was done, the position not all that comfortable in the long term. He stopped as another egg touched his magical flesh. Sans had stopped focusing on the movement needed to carry the eggs into him, so he hurriedly turned his focus to that. The egg started to move.

“I believe that’s it,” Kern sat back from Sans and started to shrink again as the egg settled into its new home. Sans sighed, reaching up to feel the sack. It was protruding, four of the large eggs more than his small stature could contain. That would be inconvenient. He might have to avoid doing anything too strenuous.

Whatever would he do?

“It is a shame that I won't be able to eat properly,” Kern added morosely. He licked the sack again, tongue dragging along the uneven surface. “Are you sure Papyrus could not-”

“No!” Sans snapped, easing himself off of the pillows. He still wasn't willing to see his brother feed Kern the magic he lived on, though, now that they had reached the point of breeding together, his reasons had grown more varied.

“We’ll do the other thing,” he said sleepily. The eggs had started to draw at his magical energy. It wasn't much, it was sudden. Between that and the process of getting them in there, he needed a nap.

“You need to be careful of your magic reserves,” Kern pointed out. He hopped onto the bed, curling against Sans’s side so his head landed on the ‘belly’ Sans had made.

“I’ll be fine,” Sans yawned, sleep calling him too strongly to expand.  
——  
“Its risky,” Kern commented, but his concern seemed to be more of a formality. He was eyeing Sans’s soul intently, licking his chops. Sans kept a firm hold on it.

“Not if you don't swallow it,” he said, not feeling great about his chances. Kern was never one to curb his appetite. If he did, there was no way Sans could go in after it. The eggs couldn't take the pressure of being swallowed.

“I’ll do my best,” Kern replied, failing to fill Sans with confidence. Still, it had been almost a week and Kern had held back. He couldn't go much longer without becoming ravenous.

Sans offered up the soul, releasing his grip on it so it sat on his hand. Kern snapped his head forward, scooping it up with his tongue.

So much for that plan.

He didn't, however, swallow it. Sans gasped as his soul rolled around Kern’s mouth, tumbled by the deft tongue as Kern sucked on it. That was a lot of intense sensation.

Sans tensed as his body got used to them, tremors wracking it with each pass of Kern’s tongue. A particularly hard pass had him arching his spine. When it ended he dropped back to the bed with a groan.

“Woah,” he got out, panting. Kern looked down at him, curious. With less care than Sans felt the action warranted, he spit the soul out into a forehand.

“Are the eggs okay?” He asked, peering at the sack. “Your reactions are quite extreme.” They hadn't used Sans’s soul since first getting Kern out of the tree, and Sans wasn't sure what all he remembered. He had been affected the same way.

“They're,” Sans shivered, an aftershock, “fine. And of course my reactions are extreme. That's my soul. I can feel everything.”

“Oh,” Kern looked down at his hand where the soul sat. Sans shivered again. That wasn't from before. Kern was gently massaging the soul right now, drawing more pleasure and more magic out of it.

Kern had also noticed the juices slicking the surface. With a happy noise he lifted it to his mouth and began to lick it clean. Sans jolted, unprepared still. He writhed, gripping the sheets and moaning lightly.

When the licking stopped and Sans could return his gaze to Kern, he found the dragon staring at him oddly.

“I like that,” he commented, unabashed. Sans, however, was very abashed and flushed darkly.

Kern went back to licking the soul, stimulating it into generating more magic, which he then slurped up. Eventually, he gave up on the slow way, as Sans had suspected he would, and popped the soul back into his mouth.

“Ahh!” Sans gasped, arching again, though less dramatically. His body was buzzing with pleasure, so it wasn't as jarring as before. It definitely raised the intensity, however. His legs bent and straightened, rubbing his feet up and down the bed as he subconsciously looked for an outlet for the pressure building in him.

There was really only one way this was going to end. Sans wasn't sure if Kern knew what it was, but he was probably going to enjoy it immensely. Sans didn't have the mental capacity left to explain it to him. He would just have to be surprised.

Sans moaned as Kern sucked on the soul, squishing it delightfully between his soft tongue and his firm upper palate, writhing on the bed with abandon. He was getting so close. Just a little more of that and he would-

“Why did you stop?” He gasped, looking blearily up at Kern. Sans's soul was back in the dragon’s forehand, leaking, but unattended.

“I’m worried about the effect this is having on you.”

“Are you-? Keep going, please. Just a little more,” Sans pleaded. Kern didn't look convinced, but licked at the soul.

“More,” Sans demanded, not even caring that it came out as a whine. Kern wrapped his tongue around the sensitive heart, winning a long moan out of Sans. He could feel his finish so close it was almost painful.

“Suck on it,” Sans begged, looking up at Kern with hazy eyelights. Kern slowly- too slowly- returned the soul to his mouth and sucked.

“Ahh!” Sans arched white hot pleasure racing through his bones. Kern hummed with surprise, the vibrations drawing out Sans’s completion. When it faded, he was laying haphazardly on the bed, Kern hovering anxiously over him.

Sans felt around the egg’s sack, one, two, three, four solid round shapes. His soul was slowly floating down from Kern’s open mouth to Sans’s sternum, fading from view as it settled into Sans’s tired but satisfied body.

“That was fun,” Kern started matter-of-factly. “We should do it again, even once the eggs are hatched.”

Sans couldn't argue with that.  
——  
“Sans!” Papyrus burst into the house at full volume. Sans startled, glad he hadn't lain down yet. “Did I miss it?”

“No, you didn't miss anything,” Sans replied, moving onto his stomach over the nest of blankets Kern had made. He had to hold himself up on his elbows and knees to avoid putting weight on the eggs. They had gotten bigger, stretching out his magic. Kern was pacing anxiously around him, which was really not helping Sans’s anxiety.

“Would you please sit down,” Sans grumbled before focusing on thinning out the magic holding the eggs inside him. Kern did, instead swishing his tail back and forth with the nervous energy. It would have to do. Sans understood, but he needed to concentrate.

The magical sack of flesh weakened slowly. The eggs shifted inside of him, lowering towards the soft bed. Eventually the magic faded all together, and the eggs dropped the last inch into the nest. Sans immediately pushed himself up, looking down at the eggs to make sure they were okay.

They sat in a neat little pile, three forming a base for the fourth. Other than a light coating of Sans’s blue magic, the shells were pristine. Sans sighed with relief and looked at Kern. The dragon was staring at the eggs intently, his tail still except for a little twitch at the very tip. Sans smiled, basking in the moment of admiring what they had made together.

Then Papyrus walked in, disrupting the peace with a coo of pure joy. That made Sans smile too.

“I’m going to be an uncle!” he squeaked, his excitement pitching his voice up past his natural range. Sans laughed, shifting back into a more comfortable position.

“Once they decide to break out of those things,” Sans cautioned. He shared Papyrus’s excitement, but now that the eggs were out of him, he had no control over the progress of their hatching.

“You said you felt them move,” Kern pointed out, without looking away from the eggs. Sans had a feeling he wouldn’t see a moment of the dragon’s attention until the hatching was over.

Sans had felt something. The eggs had gotten… restless. It was the only way he could think to describe it, and, as if to prove his story, one of the eggs rocked right in front of them. A grin broke out across Sans’s face. This was really happening. Kern inched closer, careful not to rock the bed at all. Papyrus gasped and leaned over the nest of sheets.

They all waited in not very patient silence as two of the eggs started to move more consistently, eventually rocking enough that their sibling, perched on top of them, fell to the bed. Sans felt his soul stop, even though the short drop on the soft surface probably didn’t even shake its occupant.

Eventually, cracks started to appear on one of the eggs. Sans leaned closer, excited, and somewhat terrified, to meet his offspring. What if his magic hadn’t been enough? He could have already failed as a parent. There would be so many more opportunities to do so, too.

“I can’t wait to train them!” Papyrus suddenly stage whispered. Sans looked over at him out of the corner of his sockets. There was no way Sans was going to be able to stop him, so he could give up on raising a tiny chef. “Oh, and puzzles! I have to teach them everything I know,” Papyrus continued, choking with emotion. Sans grinned a little wider.

His kids couldn’t do better than to learn from the best monster there was.

With a loud cracking sound the egg that had started moving first lost a big chunk of shell. Even Papyrus fell quiet as they watched the little one emerge. A skeletal snout poked out of the hole, probably a pretty good approximation of what Kern’s skull might look like. There was something familiar about it…

The teeth opened and bit down on the bottom edge of the hole, rocking back and forth to break another piece off and widen it. Instead of seeing more of the head, little claws appeared, digging at the shell so it crumbled away entirely along that side. It’s siblings weren’t going to wait much longer either. Two were animated, rocking back and forth, while the third was spiderwebbed with cracks.

There was a tiny growling cry from within the first egg, and a tiny little… blaster wandered out. Sans could hardly believe his sockets. It wasn’t exactly like his weapons, being very small and attached to a matching skeletal body, but the monster’s skull was startlingly similar. Had the Gaster Blasters always been dragon skulls, or had his magic given the young one that shape? They had no way of knowing.

The rest of the baby monster was definitely modeled after Kern. It was a dragon, including a tiny tail, except a skeleton as well. It stumbled forward, running into the raised wall of fabric, and promptly sat down on its hind legs. With bright white eyelights, it looked up at them and growled.

“How interesting,” Kern commented, before leaning down to lick the newly hatched monster. As he did so, the second egg hatched, its occupant bursting out with reckless abandon. They ran right into the first one, creating a tangle of awkward, boney limbs that made Sans laugh.

Reaching down, Sans picked up one of the monsters. They looked very similar, since they were so small, but, once they shook themselves off they ran up his arm to perch on his shoulder. He could feel their shaky balance, so he cupped his hands below them to make sure they wouldn’t fall. That must be the second one.

“We need names,” Sans blurted, having not considered the matter at all. Kern looked up from nudging some difficult shell off the last baby, the third was curled up against the edge of the nest, already napping. That had been fast.

Kern didn’t actually get the chance to weigh in on the topic of names before a very loud- and completely unnecessary- throat clearing noise came from the side of the bed. Sans had never figured out how Papyrus made the noise.

“I have some ideas,” Papyrus announced, producing a notebook. Sans laughed. This was going to be good.

**Author's Note:**

> My tumblr is where I: take requests, post streams, chit chat, do teasers, try out new fics, reblog a lot of skeleton porn, pimp all my favorite fics


End file.
